JPS5858445B2 - Polyester material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a molded product obtained by adding a modifying additive to a polymer whose main component is polyalkylene terephthalate or polyalkylene terephthalate. The present invention relates to a method for manufacturing a polyester molded article in which the melting conditions of additives for quality are specified.

In general, fibers and other molded products made from polyalkylene terephthalate or polyalkylene terephthalate-based polymers have been used in a variety of applications due to their excellent properties. Polymers are modified by adding modifiers such as fuel agents, antistatic agents, and heat resistance improvers.

In this case, it is extremely important to uniformly mix these modifying additives into the polymer, and various mixing methods for this purpose have been proposed.

For example, a method of adding and mixing into a polymerization reactor before the start of polymerization, during the polymerization reaction, or after the completion of the polymerization reaction, or a method of making a master chip with a high additive concentration, mixing it in chip form, and extruding it with an extruder. is given as an example.

In the method of adding additives directly into the polymerization tank, the additives are kept at high temperatures for a long time, which causes problems such as polymer depolymerization due to decomposition and promotion of side reactions.Also, the time required to change brands is very long. become longer.

Furthermore, the master chip method has problems such as insufficient mixing.

On the other hand, the post-addition method in which a mixing device is provided immediately before spinning and additives are added and mixed therein is a method that should be praised because it has fewer of these drawbacks, and this method itself is already known.

In order to avoid troubles caused by the addition of these modifying additives and to produce a polyester in which the modifying additives are substantially uniformly distributed throughout the polymer, the present inventors have detailed the conditions for the post-addition method described above. As a result of our research, we found that good results could be obtained only by melting the modifying additive under specific conditions immediately before injection molding of the polymer, avoiding decomposition of the additive. The invention was achieved.

That is, the present invention provides a polyalkylene terephthalate having a melting point of 200°C or higher or a polymer mainly composed of polyalkylene terephthalate, which has a melting point of 200 to 270°C and which is selected from carbon, hydrogen, phosphorus, nitrogen, halogen, sulfur, or oxygen. When producing a polyester molded article by adding a compound containing one or more of the above elements, the additive is heated in a melting tank with a water evaporation outlet for 10 to 700 minutes within the following temperature range. After melting, the additive is transferred to a charging tank maintained at a temperature equal to or lower than the temperature of the melting tank. The present invention relates to a method for producing a polyester molded article, characterized in that the polyester is mixed into the polymer in a mixing device provided midway from the router to the nozzle, and then extruded from the nozzle and molded.

t2+5≦t1≦t2+1o.

[Here, tl: melting temperature of additive ('C), t2: melting point of additive (°C)] An example of an apparatus system that can be used in carrying out the present invention is shown in the drawings, but of course The equipment system used for implementation is not limited to this.

Furthermore, although the illustrated example illustrates the case where fibers are obtained as a molded product, as mentioned above, the content of the present invention is to melt the modifying additive under specific conditions immediately before extrusion molding of the polymer. The present invention relates to a technique for adding the compound into a polymer, and the present invention includes not only fibers but also films or other similar shaped articles in general, which are formed by injection molding using a nozzle.

First, to explain the method of adding and mixing additives in the chip spinning method shown in Figure 1, the modifying additive is first charged into the melting tank 1, where it is melted by an appropriate heating means and kept at an appropriate temperature. After being transferred to a mixing tank 2 in which the fibers were mixed, the mixture is transferred to a mixing tank 3 provided in front of the spinning nozzle using a pump.

On the other hand, polyalkylene terephthalates to be modified are melted and extruded by an extruder 4, mixed with additives in a mixing tank 3, and spun.

In the continuous polymerization direct spinning system shown in FIG. 2, the materials are mixed in a suitable mixing device 3 provided between the polymerization tank 5 and the spinning nozzle, and then spun or chipped.

The additive melting tank used here is characterized by having an evaporated water extraction port, which allows the water contained in the reforming additive to be removed by evaporation at the same time as it is melted, and the water contained in the reforming additive to be removed by evaporation due to hydrolysis based on water contamination. Deterioration of polymer quality can be reduced.

The melting temperature of the additive must be such that water can be removed and must be higher than the melting point of the additive, but if it is too high, the additive will decompose, and if it is too low, it will take a long time to melt. I don't like it.

Therefore, the melting temperature t1 (°C) of the additive is t2+5
≦t1≦t2+100 is preferable, more preferably t2
The temperature range is +1o≦t1≦st2+104.

Here, t2 is the melting point (°C) of the additive.

The melting time of the additive varies depending on the melting temperature, type of additive, melting tank specifications, water content in the additive, etc., but if it is too short, the melting will be insufficient, and if it is too long, the additive will not melt properly. Since undesirable results such as decomposition may occur, the time required for melting and mixing is io~700 minutes, preferably 20~700 minutes.
200 minutes is appropriate.

The additive melted under the above conditions is transferred to a charging tank maintained at a temperature equal to or lower than its melting temperature, and then charged to a mixing device for mixing with the polyalkylene terephthalate.

The type of this mixing device is not particularly limited, but a mixing tank with an agitator, a static mixer, or the like may be used.

The mixing temperature and mixing time in the mixing device can be arbitrarily determined in consideration of the melting point of the polyalkylene terephthalate, etc.

The polyalkylene terephthalate or polymer containing polyalkylene terephthalate as a main component in the present invention refers to those using terephthalic acid as the acid component and alkylene glycols such as ethylene glycol, tetramethylene glycol, etc. as the glycol component. , as well as small amounts of other third components such as isophthalic acid, phthalic acid, adipic acid, parahydroxybenzoic acid, diethylene glycol, triethylene glycol, polyethylene glycol, neopentyl glycol, methoxypolyethylene glycol, sodium 5-sulfoisophthalate. It may also be a copolymer of the like, or it may further contain a matting agent, pigment, etc.

In addition, the modifying additives added in the present invention include:
Flame retardants, hygroscopic agents, antistatic agents, heat resistance improvers, containing one or more elements selected from phosphorus, nitrogen, halogen, sulfur, or oxygen in addition to carbon and hydrogen;
Various additives used to modify the main polyalkylene thirefrate, such as hydrolysis resistance improvers, pigments, mixtures of two or more of these, and various polymers containing these additives. can be given.

To give a specific example, as a twist retardant, [herein, R: the same or different aliphatic group or aromatic group with or without a substituent.

n: A positive integer of 3 or more.

] Hygroscopicity imparting agents and antistatic agents include polyalkylene glycols (including those with both ends blocked) and surfactants, and heat resistance improvers and hydrolysis resistance improvers include phosphorous acid. , trinonylphenyl phosphite,
Examples include trivalent or pentavalent phosphorus compounds such as triphenyl phosphate, phenol compounds, thiobenzanilide, diphenylthiourea, and the like.

There is no particular restriction on the amount of additives added, and the amount necessary and sufficient to achieve the purpose of modification is used.

Usually 0.05 for polyalkylene terephthalate
It is about 30%.

Hereinafter, the present invention will be specifically explained with reference to Examples.

The following examples relate to the production of fibers, but as mentioned above, it is clear that the present invention can also be applied to the production of molded products other than fibers, and is not limited to the production of fibers.

In the examples, [η] is the value of the intrinsic viscosity (d
l/g).

Examples 1-6 and Comparative Examples 1-3 The experiment was carried out using the chip spinning method shown in FIG.

A polyethylene terephthalate chip with [η] of 0.70 clll& synthesized by a conventional method was extruded using an extruder with a diameter of 301 #2. Melt extrusion at a rate of J/min, mixing temperature 280℃, stirring number 4 O in a special gate type mixing tank with stirring blades installed between the extruder and the spinning nozzle.
r, p, m, mixed with a flame retardant and spun at an average residence time of 10 minutes.

It is used as a flame retardant, and it is heated in a melting tank to the melting temperature.
The melting time was varied and melted, charged into a mixing tank for 317 minutes each, and mixed with the polyethylene terephthalate.

Table 1 summarizes the results regarding the decrease in [η] after spinning, coloring of the spun yarn, etc.

When the melting conditions of the present invention were not met, a significant decrease in [η] and coloration were observed, as well as an odor that appeared to be caused by the decomposition of the additive.

Examples 7 to 9 and Comparative Examples 4 to 5 Instead of the flame retardant in Example 1, polyethylene glycol 200 (melting point 57° C.), which was blocked at both ends, was added and mixed as an antistatic agent at a rate of 1 g/min.

Mixing temperature in the mixing tank: 285°C, stirring number: 40 rpm, m.
The average residence time was 15 minutes.

In this case, change the melting temperature and melting time in the melting tank,
Table 2 shows the results regarding the decrease in [η] after spinning, coloring of the spun yarn, etc.

When the melting conditions of the present invention were not met, there was a significant decrease in [η] and coloration.

Comparative Examples 6 to 7 Table 3 shows the spinning results when the flame retardant was melted with the water outlet of the melting tank closed in Examples 1 and 2, but the decrease in [η] after spinning was large. This is due to the fact that the water contained in the flame retardant was not removed during melting.

Examples 10 to 13 and Comparative Examples 8 to 9 In Example 1, a test was conducted in which 5% of pentabromine beryethylene terephthalate was added as a flame retardant.

Table 4 shows the test results obtained by variously changing the melting temperature and melting time in the melting tank.

All of the samples that did not meet the melting conditions of the present invention were heavily colored.

Examples 14 to 16 and Comparative Example 10 A test was conducted in which the following compound was added in an amount of 8% to polyethylene terephthalate in place of the island-releasing agent in Example 1, while changing the melting temperature and melting time of the additive.

The results are shown in Table 5. Comparative Example 10, which falls outside the scope of the present invention, had a dog color.

[Brief explanation of drawings]

FIG. 1 shows an example of the addition and mixing method in the chip spinning method of the present invention, and FIG. 2 shows an example of the addition and mixing method in the continuous polymerization direct-coupling method.

Claims (1)

[Claims] 1 Polyalkylene terephthalate with a melting point of 200°C or more or a polymer mainly composed of polyalkylene terephthalate, and an element selected from carbon, hydrogen, and phosphorus, nitrogen, halogen, sulfur, or oxygen with a melting point of 20' to 270°C. When producing a polyester molded article by adding a compound containing a species or two or more species, the additive is melted in a melting tank having a water evaporation outlet for 10 to 700 minutes within the temperature range below. , transferred to a charging tank maintained at a temperature equal to or lower than the temperature of the melting tank, and a certain amount of the melt of the additive is transferred from the polymerization tank to the nozzle or from the extruder to the nozzle. A method for producing a polyester molded product, which comprises mixing the polymer into the polymer in a mixing device provided midway through the process, and then discharging and molding the product from a nozzle.